Sorry, my bad. I have been looking at the Discourse source code all morning and I didn’t notice that was the mobile app. Makes far more sense now 
One last thing. With the allowed user api push urls in the Discourse settings, I am guessing that’s a way to allow the Discourse admin to control/limit where pushes can be sent regardless of what an external app registered? I also assume that needs to be the full URL for the push destination (e.g. http://forum.example.com/api/publish_ios)?
Thanks for the advice, will report back with how it goes and look at writing-up a howto (assuming it goes well).